Zerk Fitting Grease Amounts

Chief · 10-29-2008, 06:20 AM

Does anyone have a "rule of thumb" on how many pumps with a handheld grease gun when lubing the chassis? I am aware of the requirement to lube the U joints until new grease appears @ all 4 corners. I have always lubed the steering linkage until the rubber cups start to swell. Is this correct?

Automatic slack adjusters seem to take as much grease as I am willing to pump in. Have no idea how much to pump into the drive line slip joint as I have never seen it escaping from any opening, just hit it with 4-5 shots?

My concern is pumping too much grease into a zerk and the grease contamiating another component (such as brake linings) and creating a hazardous or potentially unsafe condition. Comments, suggestions please. Thanks..

Chief · 10-29-2008, 06:20 AM

Does anyone have a "rule of thumb" on how many pumps with a handheld grease gun when lubing the chassis? I am aware of the requirement to lube the U joints until new grease appears @ all 4 corners. I have always lubed the steering linkage until the rubber cups start to swell. Is this correct?

Automatic slack adjusters seem to take as much grease as I am willing to pump in. Have no idea how much to pump into the drive line slip joint as I have never seen it escaping from any opening, just hit it with 4-5 shots?

My concern is pumping too much grease into a zerk and the grease contamiating another component (such as brake linings) and creating a hazardous or potentially unsafe condition. Comments, suggestions please. Thanks..

jimandsue60 · 10-29-2008, 09:08 AM

I can't answer your question specifically but at my recent Camp Freightliner class they said the complete lube job should take about 2 tubes of grease.

JIM

chasfm11 · 10-29-2008, 12:26 PM

I don't know the correct answer to your question but can relate my own experience.
- the u joints and slip joint seem to take about 1/2 tube all by themselves every time. I follow the instruction to have grease come out all 4 corners on the u joints and I cover the vent hole (as instructed) on the slip joint and pump until I get pressure. I have a pistol grip type gun and building pressure takes 25-30 pulls.
- on my slack adjusters, the grease will eventually squirt out around the pins. I use the special Meritor clay based grease for them and don't use a full tube per year.
- for the king pins and all of the fittings on the steering, I pump until I get grease. Normally, it is the old grease being pushed out. Of all of those zerks, the one on the steering arm takes the most. I use a 3rd type of grease for all of these and seem to go through a tube about every 3 lubrications.

To prevent contamination, I carefully wipe off any excess of, especially around the front wheels. In 4 years, I've never had an grease spatters there. I specifically inspect the brakes every time I'm under there and have never found any grease on or around them. Around the drive shaft, however, the stuff is slung in a circle on all of the adjacent surfaces. This means that I have to clean the air filter on the air brake system carefully before starting the replacement process but I view it as just the price of admission. The drive line seems to go dry much more quickly than any place else.

JoeT · 10-30-2008, 06:16 AM

You should have received a Freightliner "Recreational Vehicle Chassis Maintenance Manual" with your coach. It tells how much lubricant to use.

Mike Canter · 10-30-2008, 04:24 PM

Here is the way I have greased things for 50 years. If it has a rubber boot that is tight with clips on it then I pump grease in until the boot expands and then I stop. Anymore than that may cause the boot to rupture. If it is not a completely sealed boot that does not have a clip on it then I pump grease in until I see new grease coming out from under the boot this gets rid of moisture and grit. I then wipe off the old grease. If it is a u-joint or a kingpin that has no tight seal then I pump in grease until I see new clean grease coming out of each and every end. This also ensures that it has pushed out the old dirty stuff. I don't really care how much grease any book tells me to use. I fill them all until I meet the above requirements.

Chief · 10-31-2008, 05:30 AM

Thanks for the replies, good suggestions one and all.

JoeT, you're right. The manual does tell how much lube for each zerk. I'm sure I read that before, just couldn't remember. Thks.

Mike, as one old W4 to another, seems like we all do things pretty much the same. Must be the military background. (Aren't all w4's old?)

Jim & chas, your replies are in line with the amount of grease that I have been using and is really the root of my initial post. My last RV (Ford Chassis) didn't take near as much grease as the FL Chassis. At each lube job I had the nagging question "why so much grease" but have come to realize that it is normal. Thks again.

David K · 01-10-2009, 05:50 PM

On my MH on a MM chassis, the grease for the slack adjusters will start to come out at the top --- near the brake drum. The first time that a tech greased mine, he did not know that and he kept on putting it in until he noticed this large "blob" near the top of the brake drum -- had about a full tube of grease up there -- he did wipe it all off so the excess would not be there. Don't know if your's is the same but, you might look up there.